One main concern for an operator is to make sure that their network provides good coverage and that calls are dropped as rarely as possible. However, when it comes to dropped calls it has been seen that this is often related to handover. The main reason for the dropped calls is that the signaling channels, Fast Associated Control Channel (FACCH) and Slow Associated Control Channel (SACCH) form the weakest link. This becomes even more emphasized when using an Adaptive Multi-Rate Full Rate (AMR FR) codec.
A number of suggestions for improving a success rate of decoding the FACCH and SACCH signaling have already been proposed, such as increasing a FACCH power, repeated FACCH and SACCH. For example is information repeatedly transmitted 5 times on channel SACCH (Slow Associated Control Channel), 23 times for SDCCH (Stand-alone Dedicated Control Channel), 34 times for FACCH (Fast Associated Control Channel), and 48 times for E-FACCH. The maximum number of retransmissions of traffic and signalling depends on the state and on the channel used.
A very simple concept to secure that the receiver of the information retrieves the information correctly is just to transmit the information repeatedly, which implies a copy of the information is sent and sent over again, retransmitted for a predetermined amount of times, or until the recipient has acknowledged that it received it. In prior art such retransmissions are performed by transmitting in a fixed direction over a whole cell in a cellular radio communication network. In a variety of circumstances such retransmissions can be stopped, e.g.:                if no such acknowledgement is forthcoming within a reasonable time, the time-out, or        the sender discovers, often through some out of band means, that the transmission was unsuccessful, or        if the receiver knows that expected data has not arrived, and so notifies the sender, or        if the receiver knows that the data has arrived, but in a damaged condition, and indicates that to the sender, the sender simply retransmits the data (which it still has a copy of).        
In retransmission using incremental redundancy, instead of retransmitting disturbed packets, sends more redundancy information to be combined in the receiver. This increases the probability of correct decoding. In 3GPP TS 04.06 retransmission and incremental redundancy is specified.
Although some of the suggested methods are expected to improve a handover performance or have already been proven to do so, through field trial or other activities, there are still reasons for further improving the performance. These are that the different suggestions may result in different gain depending on the environment. It is also not sure that all will or can be implemented and that further improvements in the speech codec will require even more robust signaling channels.
WO/97/17770 relates to an apparatus and an associated method, incorporating an antenna having an antenna pattern adaptively responsive to propagation characteristics extending between communication stations of a communication system. When the propagation characteristics are indicative of a channel exhibiting only insignificant multipath components, the antenna pattern is selected to be highly directional, and when the propagation characteristics are indicative of a channel exhibiting significant multipath components, the antenna pattern is altered to become less directional.
There are several critical parameters that affect an antenna's performance which can be adjusted during the design process for improving the performance of the antenna. Some of these parameters are resonant frequency, impedance, gain, aperture or radiation pattern, polarization, maximum power rating, efficiency and bandwidth.
In antenna design, “gain” is the logarithm of the ratio of the intensity of an antenna's radiation pattern in the direction of strongest radiation to that of a reference antenna.
The gain of an antenna is a passive phenomenon—power is not added by the antenna, but simply redistributed to provide more radiated power in a certain direction. If an antenna has a positive gain in some directions, it must have a negative gain in other directions as energy is conserved by the antenna. The gain that can be achieved by an antenna is therefore trade-off between the range of directions that must be covered by an antenna and the gain of the antenna. “Aperture”, and “radiation pattern” are closely related to gain. Aperture is the shape of the “beam” cross section in the direction of highest gain, and is two-dimensional. Radiation pattern is the three-dimensional plot of the gain, but usually only the two-dimensional horizontal and vertical cross sections of the radiation pattern are considered. Antennas with high gain typically show side lobes in the radiation pattern. Side lobes are peaks in gain other than the main lobe (the “beam”).
Further in prior art beam steering is an expression for changing of direction of the main lobe of a radiation pattern. In radio systems, beam steering may e.g. be accomplished by switching antenna elements or by changing the relative phases of the radio frequency signals driving the elements.
Accordingly, it would be highly desirable in cellular radio communication network not only to improve handover performance which is often performed by repetitive transmission but also to improve repetitive transmission of any information in both uplink and downlink connection.